U.S. Pat. No. 4,574,718 describes such an automatic sewing device, wherein the needle feed movement is always tangentially directed with respect to the seam at the individual position of stitch formation so that no mentionable forces of displacement between the workpiece and the needle occur. With such a known automatic sewing device there exists the problem that at a rotation of the rotary housing and the hook bearing the needle bar, the needle jogging drive, the thread take-up lever mechanism and the hook will be altered in their relative position resulting in stitch length variations. These stitch length variations increase proportionally with the angle of rotation per stitch about which the rotary housing and the hook bearing are swivelled.